Method of forming yarns from staple glass fibers



Feb. 12, 1957 L. P. BIEFELD ETAL METHOD OF FORMING YARNS FROM STAPLE GLASS FIBERS INVENTORS LAWRENCE P. BIEF'ELD HOMER WI DUFFEE United States Patent METHOD OF FORMING YARNS FROM STAPLE GLASS FIBERS 9 Claims. (Cl. 57164) This invention relates to an improvement in the treatment of staple glass fibers in the manufacture of yarns thereof for use in the fabrication of textile materials and the like.

To the present, yarns formed of glass fibers for use in the weaving of textiles have been manufactured principally of strands composed of continuous glass fibers formed of hundreds of filaments attenuated at high speed by drawing from a glass melting bushing. These strands are twisted and intertwisted into yarns to form threads capable of use in the weaving operations. In the manufacture of glass fibers having the necessary characteristics for processing into strands, yarns, threads and then woven into a fabric, it has been found necessary to make use of a size on the glass fiber surfaces which embodies a very important balance between bonding and lubricity so that the glass fiber filaments will be held rather firmly in the formed strand or thread to prevent difficulties in the winding, unwinding and twisting operations, yet maintain enough lubricity between fibers to provide for flexure during the subsequent processing steps.

It has been found that in the manufacture of yarns formed of glass fibers of short lengths, such as staple glass fibers, the characteristics demanded of a glass fiber treating composition are substantially different than those necessary in a size composition applied to continuous glass fibers in strand formation.

In the manufacture of a yarn of staple glass fibers or other glass fibers of discontinuous lengths, such as cut or chopped filaments, the fibers are deposited on a collecting surface to form an endless Web in which the fibers are arranged in overlapping relation in zigzag or haphazard fashion. The web is then gathered together in a bundle v or sliver and the sliver is then drafted lengthwise with the result that, under optimum conditions, the fiber concentration in any cross-section of the bundle becomes uniformly reduced and the fibers aquire greater orientation in the lengthwise direction to increase the tensile Unlike the conditions existing which establish the requirements of a size applied for the processing of continuous glass fiber filaments into strands and yarns, it is necessary that a high degree of relative movement be permitted to occur between the felted staple fibers in:

drafting but Without the danger of fiber separation and without such non-uniformity in lengthwise movement as 2,780,909 Patented Feb. 12, 1957 ice In addition, it is necessary in a system of the type described to provide for sufficient bonding, as in a size used in the treatment of continuous fibers, to hold the fibers together in a compact bundle in drafting, otherwise transverse separations would occur with the result that a bulky and fuzzy yarn would be produced lacking in strength as Well as in utility. A yarn of the type described which is incapable of maintaining its mass integrity would also be difiicult to handle in the subsequent processing steps for transformation of the yarn into a woven or knitted fabric. Although the interfelted fibers embody some degree of self-sufficiency and mass integrity, additional binding is desirable though not of a degree as great as that for a size used in the processing of continuous fibers, otherwise it would be difiicult to effect the amount of relative movement between fibers neceessary for drafting. It is important, therefore, to balance drag with sufficient bonding to maintain the integrity of the sliver and yarn formed thereof and with sufficient lubricity to enable the amount of relative movement between the fibers necessary for the drafting process.

The extent of relative movement depends somewhat upon the dimension of the fibers. For example, drafting is of lesser consequence when the sliver is fabricated of staple or discontinuous fibers of less than 3 microns in diameter. Slivers of this character may be formed into a yarn with the ratio of a 1 to 1 draft, although a greater draft is sometimes used. However, when the sliver is formed of staple fibers having a diameter of about 5-10 microns, a 10 to 20-fold draft is often required in yarn formation which means that the sliver is drafted to increase its length 10 to 20-fold.

Those who are acquainted with the characteristics of glass fibers appreciate the necessity for having a lubricant on the fiber surfaces and the desirability for providing such lubricant as soon as possible because, other- Wise, the fibers might be quickly destroyed by mutual abrasion. Properly selected lubricants not only relieve the destructive effects of abrasion during fiber and yarn formation but, in the event that they remain functionally active on the surfaces of the glass fibers in the yarn, the

ultimate properties of the yarn are enhanced.

It is conceivable that the desired amount of drag and bonding coupled with such lubricity as will enable relative movement of the fibers in forming and drafting might be secured in proper balance by a single treatment, the effectiveness of which takes into consideration the point of application, materials and diluents with a view towards the properties desired in the various stages of the process, as will hereinafter be described. Heretofore, oleaginous materials have been employed almost exclusively as a lubricant for staple glass fibers but they are lacking in many of the characteristics described above. For instance, the hydrophilic glass fiber surfaces are not receptive to the oily substances and these therefore collect on the fiber surfaces in droplets so that the entire surface of the glass fibers is not properly protected or lubricated. Being entirely organic, the oily substances exhibit little resistance to heat and lack permanence with respect to their ability to remain effective on the glass fiber surfaces.

It is an object of this invention, therefore, to formulate a composition which may be applied to staple glass fibers in yarn formation taking into consideration the characteristics of the constituents in combination and the point of application to the fibers to provide the desired balance of drag, bonding and lubricity for the processing of the glass fiber filaments from the fiber forming step to yarn formation.

Another object is to treat staple glass fibers in connection with yarn formation so that relative movement of the fibers is enabled in drafting while the fibers are held together in a compact bundle.

A further objectis to providean improved method for the formation of strands of staple or discontinuous glass fibers, and it is a related object to provide a method for use in same whereby thefibers are treated prior to deposition to form the sliver with a single composition which, during subsequent processing into a yarn and fabric, imparts the desired balance between lubricity and bonding and between bonding sufiicient to hold the fibers from lateral separation wtihout preventing relative lengthwise movement or drafting and which provides drag sufficient for proper orientation and distribution of the fibers during drafting into a yarn.

A still further object is to produce strands and yarns of staple glass fibers having the characteristics of resiliency, strength, and resistance to fiexure and abrasion, 'both in the final product and during theprocessing thereof.

,These and other objects and advantages of this invention willhereinafter appear and for purposes of illustration, .but not of limitation, an embodiment of the invention is shown in the accompanying drawings in which:

Figure l is a diagrammatic view of the glass fiber yarn forming system.

Description will be made briefly to a method of embodying featuresuof this invention for the manufacture ofa yarn in connection with the formation of staple glass fibers Referring to the drawings, Figure 1 illustrates schematically ayarn forming system wherein a multiplicity of fine, glass fibers are attenuated by one or more gaseous blasts directed from a header 11 angularly downwardly onto streams 12 of molten glasss continuously issuing from numerous openings on the underside of a glass melting furnace 13. The attenuated fibers 10 are .carried downwardly by. the blast and are deposited asa web on a moving support or conveyor, which may be in the form of a rotating drum 14 covered with a foram- .inousscreen. The peripheral speed of the drum 14 is .considerably less than that of the speed of formation of .the attenuated fibers 10 so that the individual fibers, after they are deposited on the screen, are doubled back and for th in more or less irregular formation in zigzag fashion and in overlapping relation with the result that thefibersrextend in various directions but predominantly in the longitudinal direction and the fiber concentration in any cross-section of the web 15 will be much greater than the number of streams from which the fibers are attenuated. I

A suctionbox 16 located on the underside of the drum in cooperationwith the ,top quarter thereof withdraws air through the screen in a manner to create a suction which operates tenaciously to hold the deposited fibers onto the surface of thedrum conveyor. The fibrous web 15 is subsequently forcibly withdrawn from the surface of the .conveyol as. a sliver 16 and is drafted into a strand 13 by a rapidly rotatingspool 17 onto which the yarn is wound. ..By rotating the spool at a peripheral speed greater than vthat of the drum conveyor 14 the sliver 16 is subjected to a drawing or drafting action by which the fiber concentration in cross section in the sliver is reduced and the fibers are brought into a more uniform lengthwise alignment.

The sliver may be drafted to a considerable extent without causing. breakage of the fiber bundles or the fibers since the majority of the fibers are not placed under lengthwise tension. Before the sliver 16 reaches the wind- 1ng spool 17, it is folded and formed into a compact yarn 18 or bundle which has passed through a die or tu r-r ,binizer 19 to smooth down the fiber ends and impart .a false twist to the yarn, such as is illustrated in Figure 1 of the drawing. When the relation between the linear speed of the winding spool and that of the'drum'conveyor corresponds to the extent of drafting which takes place ,in the sliver toform the yarn, and although the fibers are -not placed under considerable lengthwise tension, it is necessary that a treating composition be "applied to the surfaces thereof toimpart some degree of drag resisting relative movement between the fibers so that the fibers will become properly aligned and drafting will be uni form to maintain a desirable distribution of fibers for uni form cross section and density in the final yarn formed thereof. 7 K

In accordance with the practice of this invention, it has been found that the processing of the glass fibers into yarns and fabrics is greatly improved by the treatment of the glass fibers prior to drafting, that is during deposition of the glass fibers to form the web or in the gathering of the glass fibers to form the sliver, with a composition the active ingredients of which are con stitut ed substantially completely to wet out the surfaces of the glass fibers to coat the glass fibers throughout their lengths and which embodies the new and novel combination of characteristics in proper balance including viscosity, lubricity and bonding sufficient to cause the Wetted fibers to cling together'and impart mass integrity, yet permit sufficient relative movement for drafting as much as 10 to 20-fold without destruction by mutual abrasion. The interfelted fibers become more completely aligned and the sliver becomes uniformly decreased'in the cross-sectional dimension without breakage thereof. Such a composition 21 is sprayed upon the fibrous web 15 by the use of spray nozzle 20 to form a substantially continuous coating. g

It has been found that the characteristics of the type described may be provided by a single composition applied in a single treatment'and formulated to contain as itsessential ingredient a polymer of a polyhydric alcohol such as an alkyl glycol polymer in which the alkyl group is of the type methyl, ethyl, propyl, butyl, isobutyl, 'pentyl, octyl, decyl, octadecyl and the like, represented by'polyethylene glycol, polypropylene glycol and esters thereof, such as polyethylene glycol stearate, polyethylene glycol palmitate, polypropylene glycol oleate, polyethylene glycol linoleate and the like saturated and unsaturated fatty acid ester derivatives of the poyglycol polymers; It is preferred to make use of polyalkyl glycol polymers and esters of the type described having a molecu- 'etc. "Esters of these polyalkyl glycols and polyhydrioalcohol polymers, marketed by the Carbide & Carbon Chemical 'C or'porationjof New 'York under the trade name UCON, 'are also suitable. They may advantageously be used alone or in combination with the polyalkyl 'polymers and polyglycols. The fatty acid esters of the polyhydric alcohol polymers, which may be used in the practice of this invention, are marketed by the Onyx Oil and Chemical Company of New York.

'The efiect'iveness of the fatty acid esters j of thefpoly- "alkylglycols and'polyhydnc alcohol polymers isderived additionally from the long fatty acid'chain which forms "a part of the ester derivative. This fatty acid chain is believed 'to'be oriented away from the surfaces'of the j'glass' fibers to impart greater lubricity and there is reason tob'elie've' that this long chain fatty acid group functions as 'a protective wandwhich waves back and forth [over the surface: of the fibers to provide a protective barrier resisting fiber destruction.

The ability of these compounds completely and rapidly 'to'wetout the-glass fiber surfaces and remain as a rotective size even after the sliver is "drafteddiit'o a yain is believed to follow from the presence of the many hydroxy groups available in the polyhydric alcohol and alkyl glycol polymers which orient and seemingly have a preferential affinity for the negative hydroxy or oxy groups which exist on the glass fiber surfaces. The polyhydric alcohols and alkyl glycol polymers are thus able to function independent of other constituents embodied in the treating composition to achieve rapid wetting out of the glass fiber surfaces so as to coat the glass fibers substantially completely throughout their lengths and, because of their high molecular weight, are able to assist in the development of the desired viscosity characteristics for creating a desirable drag which controls the relative movement between the fibers in drafting.

One of the important concepts of this invention resides in the formulation of the materials in a treating composition of the type described with a diluent which is removed in part before the sliver is drafted to increase the viscosity of the coating on the glass fiber surfaces to impart drag of a character which causes the fibers to shift longitudinally relative to each other substantially uniformly to reduce the number of fibers in a cross-section of the yarn and also to reduce the cross-sectional dimension thereof during drafting.

When the treating composition is applied, as by means of a spray or the like, to the fibers in the forming hood prior to deposition onto the separating screen of the drum in web formation, the diluent should be formulated of components which are vaporizable to a limited extent at the high temperatures existing in the forming hood but not eliminated in their entirety so that some will remain in the treating composition as applied to the glass fiber surfaces to provide the desirable flowable coating of sufficient viscosity to impart a drag between fibers in drafting. Diluents having a minimum flash point of 38 C. and a minimum boiling point of about 100 C. .are suitable Where, as in the forming hood, the temperatures in the region of glass fiber forming are in the vicinity of about 100 C., but at least a portion of the diluent .should have a boiling point in excess of 100 C. Suitable tdiluents for compositions applied under these conditions may be selected of the hydrocarbons, petroleum distillates or coal tar distillates such as Stoddard solvents having a flash point above 38 C. and a boiing point range of about l2l0 C., high flash naphtha having a flash point above 38 C. and a distillation range of 150 .200 C., water having a boiling point of 100 C. and

other solvents of the type esters, ethers, alcohols and the like, used alone or in admixture with the petroleum, coal tar solvent or water.

It is preferred to apply the treating composition onto the glass fibers immediately in advance or subsequent to the deposition to form the web on the collecting screen. In this vicinity, the temperatures existing are considerably lower than those which exist in the forming hood and for purposes of achieving the desired evaporation of a portion of the diluent prior to drafting, the diluent should be formulated of components having a maximum boiling point of about 100 C. It is preferred, where possible, to make use of water because of its availability at low cost and the elimination of any danger with respect to Y fires, irritation, odors Or the like. Under other circumstances, when little if any polyhydric alcohol or alkyl glycol polymer is used, it is desirable to make use of the lower boiling organic solvents because water is unable, by itself, to lubricate the fiber surfaces although it is capable of readily wetting out the surfaces of the hydrophilic glass fibers. When organic solvents are used, the polyhydric alcohol polymers and derivatives thereof provide the dominant role in wetting out the glass fiber surfaces because of their hydroXy-groups which are able to coordinate with the highly negative and hydroxy groups existing on the surfaces of the glass fibers. 'The following are representative of suitable organic the solution.

solvents which may be used alone or in combination as the diluent in a size composition applied to the glass fibers in the vicinity of the forming screen:

Solvents Distillation range 0.)

Low boiling naphtha Ethyl alcohol Methyl ethyl ketone Ethylene dichloride uene The polyhydric alcohol polymers and derivatives thereof, being of relatively high molecular weight and soluble in water, are preferably applied, where possible, from aqueous solutions in concentrations of from 1-15 percent by weight, depending upon the molecular weight and the structure of the polymer and the region of application of the treating composition. Solutions of similar concentration have been used when the diluent is composed principally of organic solvents. It is unnecessary to rely upon the composition of the diluent to achieve proper wetting out of the glass fiber surfaces because, as previously pointed out, these polymeric compounds are constituted with a multiplicity of hydroxy groups which have an afiinity for the negative hydroxy or silicon oxide groups that exist on the glass fiber surfaces so that these materials by themselves are capable of wetting the surfaces and protecting and lubricating the glass fibers in the sliver and in the strands formed thereof by drafting.

In addition to the polyhydric alcohol polymer and derivative thereof, the treating composition may be formulated to contain a small amount of a resinous material for improving the bonding relation to maintain greater mass integrity of the sliver and setting of the fibers in the final product. For this purpose, use may be made of the organo-silicon plastics (polysiloxanes), alone or in combination with the organo-silicon fluids (polysiloxanes) It is preferred, however, that for this purpose, use be made of water soluble binders, such as hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, gelatin, starches, sodium or ammonium alginates, methyl cellulose and water soluble intermediate reaction products such as the A-stage urea-formaldehyde resins and the A-stage phenol-formaldehyde resinous reaction products.

These and others of the larger variety of synthetic resinous materials may be used when solvent solutions are employed. In general it is preferred to use a maximum of about 3 percent of such additional binder materials, the amount depending greatly upon the character of the resinous binder and the effect thereof on the viscosity of Treating compositions containing additional resins or binders of the type described are preferably applied to the sliver beyond the die or turbinizer 19 where such hardening of the resin will not interfere with the slippage of the fibers in relative movement or the free 'movement of the sliver through the die and turbinizer.

The following formulations are illustrative of compositions embodying features of this invention which may be applied to the staple fibers for yarn formation:

Example 1 10 percent by weight polyethylene glycol, average molecular weight 950-1050 percent by weight water Example 2 10 percent by weight UCON, an ester type polyglycol having a viscosity of 20-25 centistrokes at 210 F. 90 percent by weight water Example 3 mam 7 Exdmpl 4 8 percent by weight of polyethylene l colparanoia-average molecular weight 1000-1300 1 percentby weight hydroxyethyl cellulose, 70-100 centi- "stokes viscosity '91 percent by weight water Example 5 percent by weight polyethylene glycol, average molecular weight about 2000 92 percent by weight low boiling naphtha Example 6 *8 percent by weightpolypropylene'glycol, average-molecular weight' about 2000 2 percent by weight polyvinyl alcohol 30 percent by weight ethyl alcohol '60 percent by weight water Example 7 'percent by weight polyethylene glycol stearate percent by weight high 'flash naphtha 30 percent by weight toluene Though not equivalent, it has been found that the desirable balance between lubricity, bonding and drag may be achieved by the treatment of glass fibers with a coating composition formulated to contain an amine or an aminesa'lt having at least one organic g roup attached to theba'sic nitrogen atom containing at least 8 carbon atoms. These compounds are referred-to generally as cationicfactiveconipounds containing one or more basic nitrogen, phosphorous or sulphur atoms and capable of ionization in water into a cation containing the organic group of more than 8 carbon atoms. The cation is'highly attracted, possibly through the basic nitrogen atom, to the glass fiber surfaces. When insolubilized thereon, as by drying or baking, the cationic group is not readily displaced from the glass fiber surfaces except by burning off at excessive heat' and thereby remains to lubricate the fibers in the fabric. j The primary, secondary and tertiary amines and their salts, as well as the quaternary ammonium, phosphohiurn and ternary sulphonium compounds have been successfully used.

Representative of the amines are dodecylamine, octadecylarnine, pentadecylamine, dimethyldodecylamine, 'didodecylamine; hetcr'ocyclic compounds of the type pyridine, imida'zoline, quinoline, and unsaturated amines such as '9, 10 'octadecylamine and the like.

It is prefeired toemploy the water insoluble amines of the type described, the salts of which are water soluble and ionizable in aqueous medium. Such water soluble famine salts may be formed of the inorganic or organic acids, such for example as thesaltsof hydrochloric, hydrob'romicQnitric, formic, acetic, propionic, sulfonic acids and the like. The water soluble quaternary compounds used areorganic salts which are highly ionizable and formed from the reaction of quaternary bases and acids such as hydrochloric, acetic, hydrobromic and the like. In actual practice, the salt is dissolved in water or the "amine'niaybe' dissolved in an aqueous medium containing the desired inorganic or organic acid or salt of relatively low concentration. Proper fiber treatment is accomplished with a treating composition containing from 0.5 to 10 percent by weight of the amine salt and preferably, in concentrations of 0.5 to 3 percent by Weight when the organic group coordinated with the basic atom contains from 16 to 24 carbon atoms. Positive 'results have been secured with salts, such as di-heptadecyli midazoline acetate,- dodecylamine chloride, octadecyl ammonium chloride, 'octadecylamine acetate and i' the like. a

The following are further "examples illustrating com- 8 pd dons "formulated to contain *of the ty e described in the practice of this invention:

Example 8 1 percent by weight 'di-heptadecyl-imidazoline acetate 99 percentby weight water Example 9 Qlpercent by weight 'dodecylamine chloride 97 percent by Weight water Example 10 0.5 percent by weightoctadecylamine acetate 49.5 percent by Weight xylene 50.0 percent by weightStoddard solvent (a petroleum dis- 'tillate) The treating compositions set forth in Examples 1-4 and 8-10 may be applied, as by spraying upon the fibers in the collecting hood prior to their deposition on the conveyor drum 14, Formulations of Examples 5 and 6 are preferably applied subsequent to the deposition of the fibers onto the collecting screen and the composition of Example 6 is further-preferably applied to the sliver after it has passed through the die or turbinizer.

It will'be understood that lubricants may be introduced in smallamounts when necessary to increase the lubricity of the treating composition. For such purposes conventional lubricants of the textile trade may be used in amounts notto exceed 2 percent by weight of the treating composition.

Slivers formed of staple fibers surface coated with compositions of the type described before drafting may be 'formed into uniform and firmly bonded yarns Which'ca'n be "subsequently processed in the manner normal for continuous fibers into threads for use in weaving or knitting. Thus it is'possible, for the'firsttime, successfully to produceyarns of stable fibers for use in the manufacture of textiles without the necessity for taking extensive precautions in'thcir manufacture and handling during processing to avoid breakage, non-uniform thinning out or destruction'by mutual abrasion.

It willb'e understood that'other changes in the details of formulation, application and subsequent treatment may be made without departing from the spirit of the invention, especially as defined in the following claims.

We claim:

1. The method of forming yarns of staple glass fibers comprising the steps of collecting staple glass fibers in continuous fashion to form an endless web in which the fibers are interfelted in the form of a bundle but extend generally in a longitudinal direction, continuously drafting the web from a distant station whereby relative movement takes place-between the fibers to cause the fiber concentration to become thinned in cross section and by which the fibers "are brought into more uniform lengthwise alignportion of which is eliminated in the interim between the application :of the coating and drafting whereby the coating composition imparts characteristics at the time of draftingto provide a balance between bonding which causes the fibers to cling together sufiiciently to maintain mass integrity, lubricity sufficient to permit relative movement'to the fibers'while functioning to protect the fibers against destruction by mutual abrasion, and drag to control the movement for thinning of the fibers and alignment of thefibersduring drafting.

2. 1m the method of forming yarns of staple glass fibers "as claimedin claiml-in which the'coatingcomposition is applied tothe glass fibers in connection with the-depas-manor the glass fibers 'to form the web' and in which the diluent containing the polyhydric alcohol polymer dissolved therein has a boiling range the major portion of which is less than 100 C.

3. The method of forming yarns of staple glass fibers as claimed in claim 2 in which the diluent comprises an aqueous medium.

4. In the method of forming yarns of staple glass fibers, the steps of gathering staple glass fibers in continuous fashion to form an endless sliver in which the fibers are interfelted and extend generally in the longitudinal direction, continuously drafting the sliver from a distant station at a rate greater than the rate of sliver formation whereby relative movement takes place between fibers as will cause their concentration in the sliver to become reduced and the fibers arranged more nearly parallel to form a yarn, and coating the staple glass fibers prior to drafting with an aqueous composition containing from 1-15 percent by weight of a polyhydric alcohol polymer selected from the group consisting of polymers of polyhydric alcohols, their esters and their fatty acid derivatives, and maintaining a timed relation between the application of the coating and the drafting to permit elimination of sufficient of the aqueous diluent to body the coating composition and provide characteristics at the time of drafting to impart a balance between bonding which causes the fibers to cling together sufiiciently to maintain mass integrity, lubricity sufficient to permit relative movement while protecting the fibers against destruction by mutual abrasion, and drag to control the movement of the fibers for uniform thinning and alignment during draftmg.

5. The method of forming yarns of staple glass fibers as claimed in claim 4 in which the coating composition is applied to the glass fibers in connection with their forming operation, and the diluent in which the polyhydric alcohol polymer is dissolved has a flash point in excess of 38 C. and at least a portion of the diluent has a boiling range extending beyond 100 C.

6. The method of forming yarns of staple glass fibers as claimed in claim 4 in which the polyhydric alcohol polymer comprises polyethylene glycol having a molecular weight average ranging from 400 to 3000.

7. The method of forming yarns of staple glass fibers as claimed in claim 4 in which a water soluble polymer of high molecular weight is dissolved in the coating composition in amounts ranging from 13 percent by weight to increase the bonding and the viscosity of the coating composition.

8. The method of forming yarns of staple glass fibers as claimed in claim 4 in which the coating composition contains a cationic active compound selected from the groups consisting of an amine, salts thereof and quaternary ammonium compounds formed thereof in which an organic group attached directly to the basic nitrogen atom contains more than 10 carbon atoms and is present in amounts ranging from 0.5-10 percent by weight.

9. The method of producing yarns of staple glass fibers as claimed in claim 8 in which the coating composition applied to the glass fibers prior to drafting comprises an aqueous composition containing 0.5-l0 percent -by weight of a quarternary compound selected from the group consisting of an amine and salts thereof, and quaternary ammonium compounds formed thereof in which an organic group attached directly to the basic nitrogen atom contains more than 10 carbon atoms, and from l-3 percent by Weight of a water soluble high molecular weight substance to increase the binding characteristics and the viscosity of the coating composition, and in which the coating composition is applied to the glass fibers in connection with the formation of the bundle but in sufficient time to permit partial evaporation of the aqueous diluent to impart the characteristics which provide the balance between bonding to cause the fibers to cling together sufliciently in drafting References Cited in the file of this patent UNITED STATES PATENTS 2,132,702 Simpson Oct. 11, 1938 2,133,238 Slayter et al Oct. 11, 1938 2,230,271 Simpson Feb. 4, 1941 2,239,722 Lannan et a1 Apr. 29, 1941 Simison July 6, 1943 

1. THE METHOD OF FORMING YEARS OF STABLE GLASS FIBERS COMPRISING THE STEPS OF COLLECTING STAPLE GLASS FIBERS IN CONTINUOUS FASHION TO FORM AN ENDLESS WEB IN WHICH THE FIBERS ARE INTERFELTED IN THE FORM OF A BUNDLE BUT EXTEND GENERALLY IN A LONGITUDINALLY DIRECTION, CONTINUOUSLY DRAFTING THE WEB FROM A DISTANT STATION WHEREBY RELATIVE MOVEMENT TAKES PLACE BETWEEN THE FIBERS TO CAUSE THE FIBER CONCENTRATION TO BECOME THINNED IN CROSS SECTION AND BY WHICH THE FIBERS ARE BROUGHT INTO MORE UNIFORM LENGTHWISE ALIGNMENT TO FORM THE WEB INTO A YARN, AND COATING THE FIBERS PRIOR TO DRAFTING BUT AFTER THE FIBERS HAVE BEEN FORMED INTO THE ENDLESS WEB WITH A FLUID COMPOSITION CONTAINING FROM 1-15 PERCENT BY WEIGHT OF A POLYDRIC ALCOHOL POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYHYDRIC ALCOHOLS, POLYALKYL GLYCOLS AND ESTERS THEREOF AND FATTY ACID DERIVATIVES THEREOF DISSOLVED IN A SOLVENT MEDIUM A PORTION OF WHICH IS ELIMINATED IN THE INTERIM BETWEEN THE APPLICATION OF THE COATING AND DRAFTING WHEREBY THE COAT ING COMPOSTION IMPARTS CHARACTERISTICS AT THE TIME OF DRAFTNG TO PROVIDE A BALANCE BETWEEN BONDING WHICH CAUSES THE FIBERS TO CLING TOGETHER SUFFICIENTLY TO MAINTAIN MASS INTEGRITY, LUBRICITY SUFFICIENT TO PERMIT RELATIVE MOVE MENT TO THE FIBERS WHILE FUNCTIONING TO PROTECT THE FIBERS AGAINST DESTRUCTION BY MUTUAL ABRASION, AND DRAG TO CONTROL THE MOVEMENT FOR THINNING OF THE FIBERS AND ALIGNMENT OF THE FIBERS DRAFTING. 